Top Senate Democrat Chuck Schumer will oppose Supreme Court nominee Neil Gorsuch and lead a filibuster against President Donald Trump's pick, he announced Thursday.

If Democrats push to hold up the nomination, Republicans will effectively need 60 votes to confirm the 49-year-old conservative appeals judge, who parried Democratic attacks in Senate confirmation hearings this week. The minority leader from New York contended that Trump should simply pull the nomination if Gorsuch cannot reach 60 votes, rather than change the rules.

"After careful deliberation, I have concluded that I cannot support Judge Neil Gorsuch's nomination to the Supreme Court ... he will have to earn 60 votes for confirmation. My vote will be 'no,' and I urge my colleagues to do the same," Schumer said on the Senate floor.

Republicans, who hold 52 seats in the chamber, would need eight Democrats to join them to clear a procedural hurdle and confirm Gorsuch. The threat of a filibuster sets up a possible debate over whether to take the "nuclear option," or change the rules to only require a simple majority.

Schumer's opposition is hardly surprising considering the bitter partisan rhetoric surrounding the court seat, which was vacated when conservative Antonin Scalia died last year. Democrats cried foul when Republicans did not hold a hearing on Merrick Garland, a judge President Barack Obama nominated for the high court during his last year in office.

Democratic Sen. Bob Casey also said Thursday he will not vote for Gorsuch. He faces re-election next year in Pennsylvania, a state Trump won last year.

Schumer contended that Gorsuch did not show he could be independent from Trump, who "has shown almost no restraint from executive overreach." He made a claim that many Democrats leveled in hearings this week — that Gorsuch favors "the powerful over the weak."

It is not currently clear if Republicans will be able to reach the 60-vote threshold. Democrats Jeff Merkley of Oregon, Kirsten Gillibrand of New York, Sherrod Brown of Ohio and Elizabeth Warren of Massachusetts, among others, have already said they will oppose Gorsuch, according to The Associated Press.